The maintenance and repair of aircraft is a difficult and time consuming process. These activities must be routinely performed with great precision to avoid catastrophic failures.
One such repair activity is the removal and/or replacement of the spindle from a main rotor blade assembly. Spindles are used in mounting rotor blades to the main rotor of a helicopter. A series of spindles are positioned about the rotor, with the number of spindles corresponding to the number of rotor blades employed by the aircraft.
The spindles are adjustable and are used to vary the pitch of the rotor blades. By pitching the rotor blades the orientation of the aircraft can be changed. A helicopter's repair and maintenance schedule requires that the spindles must occasionally be removed from the main rotor assembly. This is a time consuming and labor intensive process. Namely, when removing the spindles, care must be taken to ensure that neither the spindle nor the surrounding rotor assembly are damaged. This is difficult because spindles are heavy and must be manipulated by hand. Furthermore, when replacing spindles, care must be taken to ensure that the spindle is repositioned and affixed in exactly the correct orientation to ensure proper operation of the aircraft. A seal is typically positioned between the spindle and the rotor. This seal, which can be formed from an elastomeric material, often results in the spindle sticking to rotor. Complicating matters further is the fact that all these activities must be performed by maintenance workers that are perched atop the aircraft.
The difficulty in removing spindles was recognized in U.S. Pat. Pub. 2010/0269321 to Noyes. This publication discloses a tool for removing a spindle and/or an elastomeric bearing from a hub. The tool includes a coupler, an arm, and a weight that is slidably engaged with the arm. The coupler is designed to be secured to a spindle, which may in turn be secured to a bearing. The weight upon the arm can be slid by the operator to remove the spindle. Namely, the weight can be moved from a first position adjacent the coupler to a second position adjacent the handle. This allows the kinetic energy of the weight to be used in removing the bearing.
The tool disclosed by Noyes has significant drawbacks. Namely, the tool relies upon kinetic energy in order to forcibly remove the spindle from the rotor. This kinetic energy could potentially damage the spindle and/or rotor. Furthermore, it requires the maintenance worker to expend a great deal of effort in order to slide the weight along the arm. The spindle removal tool of the present disclosure is designed to overcome these and other shortcomings present in the background art.